Grinding a Bottoming Tap

Fri Jun 04, 2010 6:19 pm

One of the tools needed in Helicoiling Ellie's Real Final was a bottoming tap. I have both a high end STI tap and an economical NAPA Balkamp BK 7703071 STI Tap Kit. I chose to utilize the Balkamp kit throughout this first Helicoiling exercise which would necessitate grinding the Balkamp into a bottoming tap after I got the first stage of the helicoil process done. The Balkamp was chosen as I got it on for $19.95US and my good STI tap cost me over $50.00Cdn. What follows is my first attempt at actually creating this tool.

Prior to attempting this, I talked to Cecil and a few others a lot trying to pick up some tips on how to helicoil. I got some good first hand visual experience during CubFest Northeast 2009 - but it still is not the same as doing it yourself. When it came to making a bottoming tap Cecil gave me some good advice -- take your time and keep the tool cool. I also got some great advice from Earl Fauble - one of the master machinists here on the forum. This is Earl's advice on grinding taps: